Microcalorimetric and Potentiometric Titration Studies on the Adsorption of Copper by P. putida and B. thuringiensis and Their Composites with Minerals
In order to have a better understanding on the interactions of heavy metals with bacteria and minerals in soil and associated environments, isothermal titration calorimetry (ITC), potentiometric titration and equilibrium sorption experiments were conducted to investigate the adsorption behavior of Cu2+ by Bacillus thuringiensis, Escherichia coli and their composites with minerals. The adsorption capacity of Cu(II) by bacteriamontmorillonite composite was higher than that by their individual components, whereas bacteriagoethite composite adsorbed less Cu(II) than their individual components. Potentiometric titration revealed that some new adsorption sites were created in bacteriamontmorillonite systems and some adsorption sites were masked in bacteria-goethite systems. The thermodynamic parameters were obtained from the ITC experiments. The negative △G values indicated that the adsorptions of Cu(II) by bacteria, minerals and their composites were spontaneous processes. The AH values revealed that the reactive sites on bacterial surfaces were more important than those on minerals in binding heavy metals. The positive △S values suggested the dominant inner-sphere complexes of Cu(II) on the surface of bacteria, minerals and their composites.
Adsorption Bacteria-mineral composite Copper Isothermal titration calorimetry Potentiometric titration
Linchuan Fang Peng Cai Pengxiang Li Wei Liang Qiaoyun Huang
State Key Laboratory of Agricultural Microbiology,Huazhong Agricultural University,Wuhan 430070,China
国际会议
杭州
英文
62-65
2009-10-10（万方平台首次上网日期，不代表论文的发表时间）